Lapatinib ditosylate (1) is a kinase inhibitor and is indicated in combination with: (1) capecitabine, for the treatment of patients with advanced or metastatic breast cancer whose tumors overexpress HER2 and who have received prior therapy including an anthracycline, a taxane, and trastuzumab and (2) letrozole for the treatment of postmenopausal women with hormone receptor positive metastatic breast cancer that overexpresses the HER2 receptor for whom hormonal therapy is indicated. It is marketed in USA as Tykerb®. Chemically, Lapatinib ditosylate is N-(3-chloro-4-{[(3-fluorophenyl)methyl]oxy}phenyl)-6-[5-({[2-(methylsulfonyl)ethyl]amino}methyl)-2-furanyl]-4-quinazolinamine bis(4-methylbenzenesulfonate).

U.S. Pat. No. 6,713,485 relates to substituted heteroaromatic compounds, methods for their preparation, pharmaceutical compositions containing them and their use in medicine. Specifically, U.S. Pat. No. 6,713,485 relates to quinazoline derivatives useful in treating disorders mediated by protein tyrosine kinase activity, in particular erbB-2 and/or EGFR activity.
U.S. Pat. No. 7,157,466 describes ditosylate salts of 4-quinazolineamines as well as methods of using the same in the treatment of disorders characterized by aberrant erbB family PTK activity.
WO 2008/154469 describes salts of 4-quinazolineamines as well as methods of using the same in the treatment of disorders characterized by aberrant erbB family PTK activity.
WO 2009/079541 describes crystalline forms of anhydrate ditosylate salts of 4-quinazolineamines as well as methods of using the same in the treatment of disorders characterized by aberrant erbB family PTK activity.
WO 2009/079547 describes crystalline forms of 4-quinazolineamines as well as methods of using the same in the treatment of disorders characterized by aberrant erbB family PTK activity.
US 2009/0281315 provides polymorphs of Lapatinib ditosylate, processes for preparing them, and pharmaceutical compositions comprising one or more of these polymorphs.
US 2009/0306106 provides crystalline forms of Lapatinib base, Form X and Form Y, and amorphous Lapatinib base, pharmaceutical compositions comprising the crystalline forms of Lapatinib base, and/or the amorphous Lapatinib base, and processes for their preparation.